Does Brain Plaque Point to Alzheimer's?

Feb. 6, 2008 -- The formation of brain plaque may be the first step toward Alzheimer's disease, and it can happen within a day, new research shows.

That finding, reported in tomorrow's edition of Nature, may lead to new targets for Alzheimer's treatment.

"Understanding the rules that govern plaque formation may lead us to ideas about how to intervene in the process," Bradley Hyman, MD, PhD, says in a news release.

Hyman directs the Alzheimer's Unit at the MassGeneral Institute for Neurodegenerative Disease at Massachusetts General Hospital. He is also the John Penny Professor of Neurology at Harvard Medical School.

Tracking Brain Plaque

The study was conducted in mice with genes for the production of brain plaque made of amyloid-beta protein. The mice got high-tech brain scans daily for up to three weeks.

Brain plaque formed far faster than the scientists expected. One day, the plaque wasn't there; the next day, it was.

It's not that the plaque swamped the entire brain. Plaque formed rarely, but quickly. The plaque didn't go away; it stabilized within a week.

Soon after the plaque appeared, brain cells started to distort and specialized cells called microglia appeared on the scene. The microglia didn't clear away the plaque or aggravate it. Instead, the microglia might restrict plaque growth, according to the report.

It's still not clear what starts the plaque formation process in the first place, notes Eliezer Masliah, MD, in an editorial published with the study. Masliah is a professor in the University of California, San Diego departments of neuroscience and pathology.